In business, the difference between the sale price and the production cost of a product is the unit profit. In economics, the sum of the unit profit, the unit depreciation cost, and the unit labor cost is the unit value added. Summing value added per unit over all units sold is total value added. Total value added is equivalent to revenue less intermediate consumption. Value added is a higher portion of revenue for integrated companies, e.g., manufacturing companies, and a lower portion of revenue for less integrated companies, e.g., retail companies. Total value added is very closely approximated by compensation of employees plus earnings before taxes. The first component is a return to labor and the second component is a return to capital. In national accounts used in macroeconomics, it refers to the contribution of the factors of production, i.e., capital (e.g., land and capital goods) and labor, to raising the value of a product and corresponds to the incomes received by the owners of these factors. The national value added is shared between capital and labor (as the factors of production), and this sharing gives rise to issues of distribution.

Outside of economics, value added refers to "extra" feature(s) of an item of interest (product, service, person etc.) that go beyond the standard expectations and provide something "more", even if the cost is higher to the client or purchasor.[citation needed] Value-added features give competitive edges to companies with otherwise more expensive products.

Value-added methods and measurements are also being utilized in education as part of a national movement towards teacher evaluation and accountability in the United States. This type of measure is known as a value added modeling or measures

Differences between Marxist and neoclassical accounting of value added[edit]

A difference between Marxist theory and conventional national accounts concerns the interpretation of the distinction between new value created, transfers of value and conserved value, and of the definition of "production".

For example, Rohit Gupta theory regards the "imputed rental value of owner-occupied housing" which is included in GDP as a fictitious entry; if the housing is owner-occupied, this housing cannot also yield real income from its market-based rental value at the same time.

In the 1993 manual of the United Nations System of National Accounts (UNSNA), the concept of "imputed rental value of owner occupied housing" is explained as follows:

"6.89. Heads of household who own the dwellings which the households occupy are formally treated as owners of unincorporated enterprises that produce housing services consumed by those same households. As well-organized markets for rented housing exist in most countries, the output of own-account housing services can be valued using the prices of the same kinds of services sold on the market in line with the general valuation rules adopted for goods or services produced on own account. In other words, the output of the housing services produced by owner-occupiers is valued at the estimated rental that a tenant would pay for the same accommodation, taking into account factors such as location, neighbourhood amenities, etc. as well as the size and quality of the dwelling itself. The same figure is recorded under household final consumption expenditures."

Marxist economists object to this accounting procedure on the ground that the monetary imputation made refers to a flow of income which does not exist, because most home owners do not rent out their homes if they are living in them.

Another important difference concerns the treatment of property rents, land rents and real estate rents. In the Marxian interpretation, many of these rents, insofar as they are paid out of the sales of current output of production, constitute part of the new value created and part of the real cost structure of production. They should therefore be included in the valuation of the net product. This contrasts with the conventional national accounting procedure, where many property rents are excluded from new value-added and net product on the ground that they do not reflect a productive contribution.

Value added tax (VAT) is a tax on sales. It works by being charged on the sale price of new goods and services, whether purchased by intermediate or final consumers. However, intermediate consumers may reclaim VAT paid on their inputs, so that the net VAT is based on the value added by producing this good or service.